1. Field of the Invention
This invention relates to a focus adjusting device for a binocular. More particularly, it is concerned with improvement in the manipulating device for the focus adjustment of the optical system in the binocular.
In the conventional focus adjusting device for a binocular, there has mostly been used a type, in which a focus adjusting ring is rotated by bending and stretching actions of fingertip to carry out focusing of the optical system to an object in a distance place, hence the focusing operation lacks in quickness. As the result, when it is desired to view a telescopic object, such delayed focusing action often causes missing of the object out of view. Also, when the telescopic object is quick moving such as, for example, sport competition, horse racing, theatrical performances, and others, it is very difficult to carry out the focus adjusting operation by correcting focus of the object so as to constantly bring a clear image of the object into view.